Truss-shaped engine pylon and method of making same

ABSTRACT

An aircraft engine pylon comprises a top wall, a bottom wall, a left side wall, and a right side wall. The left side wall includes a left truss structure along with a left upper ledge and a left lower ledge. The right side wall includes a right truss structure along with a right upper ledge and a right lower ledge. The top wall is joined with the left upper ledge and the right upper ledge and an upper truss structure is formed in the left upper ledge, the right upper ledge, and the top wall. The bottom wall is joined with the left lower ledge and the right lower ledge and a lower truss structure is formed in the left lower ledge, the right lower ledge, and the bottom wall.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention relate to pylons that couple anexternally attached component to an aircraft wing or fuselage. Moreparticularly, embodiments of the present invention relate to aircraftengine pylons constructed from truss-shaped components that are joinedtogether.

2. Description of the Related Art

An aircraft pylon secures an aircraft engine, typically a high-bypassengine, to an aircraft wing. The pylon performs a number of criticalfunctions such as supporting the engine weight, the fairings andsystems, providing a fire and vapor barrier between the engine and thewing, transmitting the engine thrust into the structure of the airplane,supporting engine nacelle and thrust reverser in the optimum aerodynamiclocation, and the like. A typical pylon may include nearly a hundredparts, which may be held together by thousands of fasteners. Theassembly of the pylon may include drilling hundreds of holes forcoupling the parts together as well as extensive corrosion protectionand sealing of joints and fasteners. The strength of the materialsrequired for the pylon may make the drilling process very timeconsuming. Furthermore, the use of mechanical fasteners requiresconsiderable overlapping of the joining surfaces which adds weight andcost. Thus, the production of aircraft engine pylons from a large numberof joined-together components is time and labor intensive with a highpart count and corresponding high cost.

One approach to alleviate some of these problems involves casting theaircraft pylons as a single integrated molded structure. However,castings of this nature have a high cost and present logistical issues.For example, casting of a flowable metal into a mold that forms thepylon is limited by the maximum pour weight of the metal foundry, whichin turn may limit the size of the pylon that can be produced or mayforce a number of castings of portions of the pylon to be produced thatneed to be joined together. The use of fasteners to join the portionstogether leads to the problems discussed above.

SUMMARY OF THE INVENTION

Embodiments of the present invention solve the above-mentioned problemsand provide a distinct advance in the art of aircraft pylons. Moreparticularly, embodiments of the invention provide aircraft enginepylons constructed from truss-shaped components that are joined togethersuch that the joints lie within truss structures.

Various embodiments of the invention may provide an aircraft enginepylon that comprises a top wall, a bottom wall, a left side wall, and aright side wall. The left side wall may include a left truss structurealong with a left upper ledge and a left lower ledge. The right sidewall may include a right truss structure along with a right upper ledgeand a right lower ledge. The top wall may be joined to the left upperledge and the right upper ledge. An upper truss structure may be formedin the left upper ledge, the right upper ledge, and the top wall. Thebottom wall may be joined with the left lower ledge and the right lowerledge. A lower truss structure may be formed in the left lower ledge,the right lower ledge, and the bottom wall.

The pylon may include a plurality of wing attachment lugs coupled to theleft side wall, the right side wall, and the top wall that is configuredto couple the pylon to an aircraft wing. The pylon may further includean engine attachment interface and a plurality of engine attachment lugscoupled to the left side wall and the right side wall and configured tocouple the pylon to the aircraft engine.

Various other embodiments of the pylon may comprise a forward trussunit, an aft truss unit, and a central engine mount interface. Theforward truss unit may include a forward upper truss structure, aforward lower truss structure, a forward left truss structure, and aforward right truss structure and may be configured to couple the pylonto the aircraft engine. The aft truss unit may include an aft uppertruss structure, an aft lower truss structure, an aft left trussstructure, and an aft right truss structure and may be configured tocouple the pylon to an aircraft wing. The central engine mount interfacemay be configured to couple the pylon to the aircraft engine and may becoupled to the aft portion of the forward truss unit and to the forwardportion of the aft truss unit.

Various embodiments of the invention may provide a method ofconstructing an aircraft engine pylon. The steps of the method mayinclude forming a left side wall with a left upper ledge and a leftlower ledge and forming a right side wall with a right upper ledge and aright lower ledge. The method may also include joining a top wall thatmay include a portion of an upper truss structure to the left upperledge with a single joint and the right upper ledge with a single joint.The method may further include joining a bottom wall that may include aportion of a lower truss structure to the left lower ledge with a singlejoint and the right lower ledge with a single joint. The method mayadditionally include forming a portion of the upper truss structure inthe left upper ledge and the right upper ledge and forming a portion ofthe lower truss structure in the left lower ledge and the right lowerledge.

Various other embodiments of the method may comprise the steps offorming a forward truss unit including a forward upper truss structure,a forward lower truss structure, a forward left truss structure, and aforward right truss structure, and configured to couple the pylon to theaircraft engine. The method may also include the step of forming an afttruss unit including an aft upper truss structure, an aft lower trussstructure, an aft left truss structure, and an aft right trussstructure, and configured to couple the pylon to an aircraft wing. Themethod may further include the step of forming a central engine mountinterface including a plurality of engine mount lugs and configured tocouple the pylon to a portion of the aircraft engine. The method mayadditionally include the steps of joining the aft portion of the forwardtruss unit to the central engine mount interface and joining the forwardportion of the aft truss unit to the central engine mount interface.

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

Other aspects and advantages of the present invention will be apparentfrom the following detailed description of the embodiments and theaccompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Embodiments of the present invention are described in detail below withreference to the attached drawing figures, wherein:

FIG. 1 is a side cutaway view of an aircraft engine and an aircraft wingshowing a pylon constructed in accordance with at least a firstembodiment of the present invention that couples the aircraft engine tothe aircraft wing;

FIG. 2 is a perspective view from the forward end of the pylon;

FIG. 3 is a perspective view from the aft end of the pylon;

FIG. 4 is an exploded view of the pylon showing a top wall, a bottomwall, a left side wall, a right side wall, an upper closeout fitting,and a lower closeout fitting;

FIG. 5 is an exploded view of a portion of the pylon showing a solid topwall with a plurality of tabs, a solid bottom wall with a plurality oftabs, the left side wall including a left upper ledge and a left lowerledge both with tabs at opposing ends, and the right side wall includinga right upper ledge and a right lower ledge both with tabs at opposingends;

FIG. 6 is a perspective view of the portion of the pylon of FIG. 5 withthe top wall, the left side wall, the right side wall, and the bottomwall all joined together with one joint between any two adjacent walls;

FIG. 7 is a top view of the pylon of FIG. 6;

FIG. 8 is a perspective view of the pylon of FIG. 6 further including anupper truss structure and a lower truss structure;

FIG. 9 is a top view of the pylon of FIG. 8;

FIG. 10 is an exploded view of the portion of the pylon of FIG. 5further including a portion of the upper truss structure formed in thetop wall and a portion of the lower truss structure formed in the bottomwall;

FIG. 11 is a perspective view of the portion of the pylon of FIG. 10with the top wall, the left side wall, the right side wall, and thebottom wall all joined together with one joint between any two adjacentwalls;

FIG. 12 is a top view of the pylon of FIG. 11;

FIG. 13 is a perspective view of the portion of the pylon of FIG. 11further including a greater portion of the upper truss structure formedin the top wall and a greater portion of the lower truss structureformed in the bottom wall;

FIG. 14 is a top view of the pylon of FIG. 13;

FIG. 15 is a perspective view of the portion of the pylon of FIG. 13further including a portion of the upper truss structure formed in theupper left ledge and the upper right ledge and a portion of the lowertruss structure formed in the lower left ledge and the lower rightledge;

FIG. 16 is a top view of the pylon of FIG. 15;

FIG. 17 is a perspective view from the forward end of a secondembodiment of the pylon;

FIG. 18 is a perspective view from the aft end of the second embodimentof the pylon;

FIG. 19 is a perspective view from the forward end of a third embodimentof the pylon;

FIG. 20 is a perspective view from the aft end of the third embodimentof the pylon;

FIG. 21 is an exploded view of the third embodiment of the pylon;

FIG. 22 is a perspective view of a portion of a fourth embodiment of thepylon;

FIG. 23 is a front end view of a cross section of the fourth embodimentof the pylon showing four walls of the pylon separated;

FIG. 24 is a front end view of a cross section of the fourth embodimentof the pylon showing a corner of the pylon;

FIG. 25 is a front end view of a cross section of the fourth embodimentof the pylon showing a corner of the pylon including a splatter guard;

FIG. 26 is a flow diagram of at least a portion of the steps of a firstembodiment of a method of creating a pylon;

FIG. 27 is a flow diagram of at least a portion of the steps of a secondembodiment of a method of creating a pylon;

FIG. 28 is a flow diagram of at least a portion of the steps of a thirdembodiment of a method of creating a pylon;

FIG. 29 is a flow diagram of at least a portion of the steps of a fourthembodiment of a method of creating a pylon;

FIG. 30 is a flow diagram of at least a portion of the steps of a fifthembodiment of a method of creating a pylon; and

FIG. 31 is a flow diagram of at least a portion of the steps of a sixthembodiment of a method of creating a pylon.

The drawing figures do not limit the present invention to the specificembodiments disclosed and described herein. The drawings are notnecessarily to scale, emphasis instead being placed upon clearlyillustrating the principles of the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The following detailed description of the invention references theaccompanying drawings that illustrate specific embodiments in which theinvention can be practiced. The embodiments are intended to describeaspects of the invention in sufficient detail to enable those skilled inthe art to practice the invention. Other embodiments can be utilized andchanges can be made without departing from the scope of the presentinvention. The following detailed description is, therefore, not to betaken in a limiting sense. The scope of the present invention is definedonly by the appended claims, along with the full scope of equivalents towhich such claims are entitled.

An aircraft engine pylon 10 for securing an aircraft engine 12 to a wing14 of an aircraft as constructed in accordance with various embodimentsof the current invention is shown in FIG. 1. The aircraft may be acommercial airliner with a high-bypass jet engine, although otheraircraft and engine combinations are possible. The pylon 10 may couplethe upper portion of the engine 12 to the leading edge and under side ofthe aircraft wing 14, but other mounting arrangements may be used.

Although the pylon 10 is shown in the figures and described herein asbeing configured to secure the aircraft engine 12 to the aircraft wing14, embodiments of the present invention may secure an externallymounted system, such as a fuel tank, a sensor pod, an expendableordnance, or the like, to the aircraft wing 14 or aircraft fuselage.

A first embodiment of the pylon 10 is shown in FIGS. 2-4 and may be of agenerally elongated box shape with a forward portion 16 and an aftportion 18 and further may have a transverse cross-sectional shape of anisosceles trapezoid or a rectangle, in some embodiments. As best shownin FIG. 4, the pylon 10 may be constructed from separately producedcomponents 20 that broadly comprise a top wall 22, a bottom wall 24, aleft side wall 26, a right side wall 28, an upper closeout fitting 30,and a lower closeout fitting 32. The pylon 10 generally requires highstrength and light weight and accordingly the components 20 may bemanufactured from a material such as titanium or titanium alloys likeTi-6Al-4V.

The top wall 22 generally provides mechanical strength and support foran upper wing attachment lug 34 that is coupled to the upper surface ofthe top wall 22. The top wall 22 may include at least a portion of anupper truss structure 36 that includes a plurality of straight, slendertruss members 38. The truss members 38 may intersect and be coupled toone another by a plurality of truss nodes 40, such that each truss node40 may receive a portion of the truss members 38. The top wall 22 mayalso include a top central rail 42 that is positioned in line with thelongitudinal axis of the pylon 10 and along which may be located aportion of the truss nodes 40.

The upper wing attachment lug 34 generally provides a connection fromthe pylon 10 to the leading edge of the aircraft wing 14. The upper wingattachment lug 34 may be connected to the top central rail 42 and mayprotrude upward with a slender width and increasing height extending inthe aft direction. The upper wing attachment lug 34 may also include anopening 44 which couples to the aircraft wing 14.

The bottom wall 24 may possess a similar structure to the top wall 22and may include a portion of a lower truss structure 46 with a bottomcentral rail 48 and a plurality of truss members 38 coupled together bya plurality of truss nodes 40. The bottom wall 24 may also include acentral portion 50 of a forward engine attachment interface 52positioned near the forward edge of the bottom wall 24.

The left side wall 26 may include a left truss structure 54 which may becoupled to a left upper side rail 56 and a left lower side rail 58. Theleft truss structure 54 may also include a plurality of truss members 38coupled together by a plurality of truss nodes 40. The left upper siderail 56 and the left lower side rail 58 may be positioned in line withthe longitudinal axis of the pylon 10 and may be coupled with theplurality of truss nodes 40 of the left side wall 26. Further coupledalong the length of the left upper side rail 56 and the left lower siderail 58 may be several truss nodes 40 from the top wall 22 and thebottom wall 24, such that the left side wall 26 retains a portion ofeach of the truss nodes 40 from the top wall 22 and the bottom wall 24coupled thereto.

A left aft wing attachment lug 60 may be coupled at the aft end of theleft upper side rail 56. A pair of left aft engine attachment lugs 62may be coupled to the aft section of the left side wall 26. Coupled tothe forward end of the left lower side rail 58 may be a left portion 64of the forward engine attachment interface 52.

The right side wall 28 may be substantially the mirror image of the leftside wall 26 and may include a right truss structure 66 which may becoupled to a right upper side rail 68 and a right lower side rail 70.The right truss structure 66 may also include a plurality of trussmembers 38 coupled together by a plurality of truss nodes 40. The rightupper side rail 68 and the right lower side rail 70 may be positioned inline with the longitudinal axis of the pylon 10 and may be coupled withthe plurality of truss nodes 40 of the right side wall 28. Furthercoupled along the length of the right upper side rail 68 and the rightlower side rail 70 may be several truss nodes 40 from the top wall 22and the bottom wall 24, such that the left side wall 26 retains aportion of each of the truss nodes 40 from the top wall 22 and thebottom wall 24 coupled thereto.

A right aft wing attachment lug 72 may be coupled at the aft end of theright upper side rail 68. A pair of right aft engine attachment lugs 74may be coupled to the aft section of the right side wall 28. Coupled tothe forward end of the right lower side rail 70 may be a right portion76 of the forward engine attachment interface 52.

The left aft wing attachment lug 60 and the right aft wing attachmentlug 72 generally protrude aftward from the pylon 10 and may both includean opening 78, such that the two openings 78 are in alignment. Throughthe two openings 78, the pylon 10 may couple to a portion of theaircraft wing 14.

The left aft engine attachment lugs 62 and the right aft engineattachment lugs 74 generally couple the pylon 10 to the aft region ofthe aircraft engine 12. These lugs 62, 74 may include a plurality ofholes 80 through which the engine 12 may be mounted.

The forward engine attachment interface 52, which comprises the leftportion 64, the center portion 50, and the right portion 76, generallycouples the pylon 10 to the central region of the aircraft engine 12.The forward engine attachment interface 52 may include a plurality ofholes 82 near the left and right sides of the interface 52 through whichthe engine 12 may be mounted.

The upper closeout fitting 30 generally couples to the upper portion ofthe aft section of the top wall 22, the left side wall 26, and the rightside wall 28. The upper closeout fitting 30 may include an upper plate84 coupled to a lower plate 86 at an angle therebetween. The upper plate84 may include a larger rectangular shape coupled on one side to asmaller rectangular shape. The lower plate 86 may be of the smallerrectangular shape, such that the combination of the upper plate 84 andthe lower plate 86 forms a “T” shape.

The lower closeout fitting 32 generally couples to the central and lowerportions of the aft section of the left side wall 26 and the right sidewall 28, as well as the aft portion of the bottom wall 24. The lowercloseout fitting 32 may include an upper section 88 coupled at an angleto a middle section 90 coupled at an angle in turn to a lower section92. The upper section 88 may also be attached to the lower plate 86 ofthe upper closeout fitting 30. The lower section 92 may couple to theaft portion of the bottom wall 24. The middle section 90 may alsoinclude a lower wing attachment lug 94 protruding in the aft direction.The lower wing attachment lug 94 may include an opening 96 through whichthe pylon 10 may be attached to the aircraft wing 14.

In a second embodiment, as shown in FIGS. 17-18, the pylon 10 mayinclude a left forward wing attachment lug 98 and a right forward wingattachment lug 100 instead of the upper wing attachment lug 34 asdescribed above. The left forward wing attachment lug 98 may be coupledto the left upper side rail 56, and may include an opening 102 whichprovides a first connection from the pylon 10 to the leading edge of theaircraft wing 14. The right forward wing attachment lug 100 may becoupled to the right upper side rail 68, and may include an opening 104which provides a second connection from the pylon 10 to the leading edgeof the aircraft wing 14. Furthermore, in various embodiments, since theupper wing attachment lug 34 is not present and support of that load isnot necessary, then the top central rail 42 and the bottom central rail48 may not be present as well.

The components 20 of the aircraft engine pylon 10—the top wall 22, thebottom wall 24, the left side wall 26, and the right side wall 28—may bejoined together to form the pylon 10. The joining process may includewelding of the components 20 together using electron-beam welding orsimilar welding techniques for use with titanium and titanium alloys.The upper closeout fitting 30 and the lower closeout fitting 32 may bejoined to the pylon 10 by welding or by fastening.

Generally, the left side wall 26 and the right side wall 28 are formedto include the left truss structure 54 and the right truss structure 66,respectively. The forming may include casting, forging, machining, orthe like. The left side wall 26 may also include the left upper siderail 56 and the left lower side rail 58. Likewise, the right side wall28 may include the right upper side rail 68 and the right lower siderail 70.

In addition, the left side wall 26 may include a left upper ledge 106coupled to the left upper side rail 56 and a left lower ledge 108coupled to the left lower side rail 58. The left upper ledge 106 and theleft lower ledge 108 may be substantially planar and may extend from theleft side wall 26 a short length toward the center of the pylon 10. Theleft upper ledge 106 may generally align with the top wall 22, and theleft lower ledge 108 may generally align with the bottom wall 24. Theright side wall 28 may include a right upper ledge 110 and a right lowerledge 112 that are generally the mirror image of the left upper ledge106 and the left lower ledge 108. Accordingly, the right upper ledge 110may generally align with the top wall 22 and the right lower ledge 112may generally align with the bottom wall 24.

In certain embodiments, the top wall 22 and the bottom wall 24 may beformed to be generally planar solid slabs of material as shown in FIG.5. The left side of the top wall 22 may be positioned in alignment withand joined with the left upper ledge 106, as seen in FIGS. 6-7. Theright side of the top wall 22 may be positioned in alignment with andjoined with the right upper ledge 110. The left side of the bottom wall24 may be positioned in alignment with and joined with the left lowerledge 108. The right side of the bottom wall 24 may be positioned inalignment with and joined with the right lower ledge 112. The joiningprocess, which may include welding, generally results in a plurality ofjoints 114, that are located along joint lines 116 at the interfaceswhere the four walls 22, 24, 26, 28 are joined. In such embodiments,there may be one joint 114 per joint line 116 for a total of four joints114. Since the left side wall 26 and the right side wall 28 are formedwith ledges 106, 108, 110, 112 that extend away from the left side wall26 and the right side wall 28, the joints 114 occur away from the leftupper side rail 56, the left lower side rail 58, the right upper siderail 68, and the right lower side rail 70, which is where structuralloading of the pylon 10 may occur.

After the top wall 22 and the bottom wall 24 are joined to the left sidewall 26 and the right side wall 28, the top wall 22, the left upperledge 106, and the right upper ledge 110 may be machined to form theupper truss structure 36. Additionally, the bottom wall 24, the leftlower ledge 108, and the right lower ledge 112 may be machined to formthe lower truss structure 46. In various embodiments, the upper trussstructure 36 and the lower truss structure 46 may be formed such thatthe truss nodes 40 located in the ledges 106, 108, 110, 112 and thespace in between the truss nodes 40 are positioned along the joint lines116, as seen in FIGS. 8-9. As a result, the joints 114 between the topwall 22, the bottom wall 24, the left side wall 26, and the right sidewall 28 are isolated to the truss node 40 locations, such that failureof a joint 114 remains isolated to the loss of a single truss node 40.In contrast, if the sides of the pylon 10 were joined together along therails, 56, 58, 68, 70, the failure of a single joint may lead to theseparation of two sides of the pylon 10 and in turn to the failure ofthe pylon 10.

In other embodiments, after the joining process, the upper trussstructure 36 and the lower truss structure 46 may be formed, for exampleby machining, such that the joint lines 116 may be positioned along thetruss members 38 connected to the truss nodes 40 located in the ledges106, 108, 110, 112, as seen in FIGS. 2-4. Consequently, the joints 114between the top wall 22, the bottom wall 24, the left side wall 26, andthe right side wall 28 are further isolated to the truss members 38,such that failure of a joint 114 remains isolated to the loss of asingle truss member 38.

In various embodiments, the top wall 22, the bottom wall 24, the leftupper ledge 106, the left lower ledge 108, the right upper ledge 110,and the right lower ledge 112 may all be formed to include an extendingtab 118 that protrudes longitudinally where the four walls 22, 24, 26,28 are joined. The tab 118 may be an integral part of the walls 22, 24and the ledges 106, 108, 110, 112, as seen in FIGS. 5-7, that isutilized for the joining process and then is machined away afterwards.

In some embodiments, the top wall 22 and the bottom wall 24 may beformed to include portions of the upper truss structure 36 and the lowertruss structure 46, as shown in FIGS. 10-12. A plurality of holes 120may be cut, machined, or cast into the top wall 22 and the bottom wall24 before the joining process. The holes 120 may be cut to form thoseportions of the upper truss structure 36 and the lower truss structure46 that do not cross the joint lines 116. Thus, the top wall 22 and thebottom wall 24 may be joined to the left side wall 26 and the right sidewall 28 with four continuous joint lines 116. Then, additional holes 120may be cut into the top wall 22 and the bottom wall 24 to form the trussnodes 40 along the ledges 106, 108, 110, 112 and the spacestherebetween. These embodiments may or may not include the tabs 118, asdescribed above.

In various embodiments, the top wall 22 and the bottom wall 24 may beformed to include a majority of the upper truss structure 36 and thelower truss structure 46, as shown in FIGS. 13-14. The holes 120 in thetop wall 22 and the bottom wall 24 that are adjacent to the left sidewall 26 and the right side wall 28 may be machined, cut, or cast towithin a small distance from the joint lines 116, such that the top wall22 and the bottom wall 24 may include a sacrificial joint material 122in these areas. Thus, the top wall 22 and the bottom wall 24 may bejoined to the left side wall 26 and the right side wall 28 with fourcontinuous joint lines 116. After joining, the holes 120 in the top wall22 and the bottom wall 24 that are adjacent to the left side wall 26 andthe right side wall 28 may be further machined or cut to remove thesacrificial joint material 122 thereby forming the truss nodes 40 andthe spaces therebetween. These embodiments may or may not include thetabs 118, as described above.

In other embodiments similar to those discussed above, the holes 120 inthe top wall 22 and the bottom wall 24 that are adjacent to the leftside wall 26 and the right side wall 28 may be machined, cut, or cast toinclude a substantial portion, but not all, of the space between thetruss nodes 40, as shown in FIGS. 15-16. Accordingly, only a smallportion of sacrificial joint material 122 may be present directlyadjacent to the truss nodes 40. In these embodiments, a plurality ofjoints 114 may occur along each joint line 116, as opposed to one joint114 for each joint line 116 in the embodiments described above. Afterthe joining process, the sacrificial joint material 122 may be removed.Furthermore, these embodiments may or may not include the tabs 118, asdescribed above.

In yet other embodiments, the left side wall 26 and the right side wall28 may be formed to include a substantial portion of truss members 38 ofthe upper truss structure 36 and the lower truss structure 46, as shownin FIGS. 2-4. The top wall 22 may include a portion of the upper trussstructure 36, and the bottom wall 24 may include a portion of the lowertruss structure 46. The left side wall 26 and the right side wall 28 maybe joined to the top wall 22 and the bottom wall 24 with a plurality ofjoints 114 being made along each of the four joint lines 116. The joints114 occur along the truss members 38 of the upper truss structure 36 andthe lower truss structure 46. As discussed above, this approach isolatesthe failure of a joint 114 to a single truss member 38.

In various embodiments discussed above, wing attachment lugs, such asthe left aft wing attachment lug 60 or the right aft wing attachment lug72, and engine attachment lugs, such as the left aft engine attachmentlug 62 or the right aft engine attachment lug 74, may be included withone or more of the walls 22, 24, 26, 28 of the pylon 10. The lugs may beformed by casting, machining, joining, or fastening.

In a third embodiment shown in FIGS. 19-21, the pylon 10 may comprise aforward truss unit 124, an aft truss unit 126, a central engine mountinterface 128, a spigot fitting 130, and an aft wing attachment fitting132.

The forward truss unit 124 generally provides support for coupling thepylon 10 to the engine 12. The forward truss unit 124 may be of agenerally elongated box shape with a transverse cross-sectional shape ofan isosceles trapezoid or a rectangle. The forward truss unit 124 mayinclude a forward top wall 134, a forward bottom wall 136, a forwardleft side wall 138, and a forward right side wall 140. The forward topwall 134 may include a forward upper truss structure 142. The forwardbottom wall 136 may include a forward lower truss structure 144. Theforward left side wall 138 may include a forward left truss structure146. The forward right side wall 140 may include a forward right trussstructure 148. The forward engine attachment interface 52, as describedabove, may also be coupled to the leading edge of the forward truss unit124.

The aft truss unit 126 generally provides support for coupling the pylon10 to the aircraft wing 14. Like the forward truss unit 124, the afttruss unit 126 may be of a generally elongated box shape with atransverse cross-sectional shape of an isosceles trapezoid or arectangle. The aft truss unit 126 may include an aft top wall 150, anaft bottom wall 152, an aft left side wall 154, and an aft right sidewall 156. The aft top wall 150 may include an aft upper truss structure158. The aft bottom wall 152 may include an aft lower truss structure160. The aft left side wall 154 may include an aft left truss structure162. The aft right side wall 156 may include an aft right trussstructure 164. The aft truss unit 126 may also include a left wingattachment lug 166 coupled to the upper section of the forward portionof the aft left side wall 154 and a right wing attachment lug 168coupled to the upper section of the forward portion of the aft rightside wall 156. The left wing attachment lug 166 and the right wingattachment lug 168 generally couple the pylon 10 to the leading edge ofthe aircraft wing 14.

The central engine mount interface 128 generally couples the pylon 10with an aft portion of the aircraft engine 12. The central engine mountinterface 128 may be of rectangular block shape and a plurality of leftengine attachment lugs 170 and a plurality of right engine attachmentlugs 172. Each of the left engine attachment lugs 170 and the rightengine attachment lugs 172 may include one or more openings 174 throughwhich the central engine mount interface 128 may be physically attachedto the aircraft engine 12. The central engine mount interface 128 may becoupled to the aft portion of the forward truss unit 124 and to theforward portion of the aft truss unit 126.

The spigot fitting 130 generally couples the pylon 10 to a portion ofthe aircraft wing 14. The spigot fitting 130 may be flat and relativelythin compared to its surface area with a generally “T” shape. The spigotfitting 130 may include an outward protruding cylindrically-shapedcoupler 176 that engages the aircraft wing 14. The spigot fitting 130may be coupled to the forward portion of the top wall 22.

The aft wing attachment fitting 132 generally couples the trailing edgeof the pylon 10 to the mid to aft portion of the aircraft wing 14. Theaft wing attachment fitting 132 may be flat and relatively thin comparedto its surface area with a roughly pentagonal shape. The aft wingattachment fitting 132 may be coupled to the aft portion of the afttruss unit 126.

The forward truss unit 124 and the aft truss unit 126 may be joined tothe central engine mount interface 128 to form the main structure of thepylon 10, as seen in FIG. 21. The joining process may include weldingusing electron-beam welding or similar welding techniques for use withtitanium and titanium alloys. The spigot fitting 130 and the aft wingattachment fitting 132 may be joined to the pylon 10 by welding or byfastening.

The central engine mount interface 128, the spigot fitting 130, and theaft wing attachment fitting 132 may be formed by casting or machiningtitanium and/or titanium alloys. The forward truss unit 124 and the afttruss unit 126 comprise similar components to the first and secondembodiments of the pylon 10 described above, and thus the forward trussunit 124 and the aft truss unit 126 may be formed and/or assembled inany of the ways described above. For example, the forward and aft leftside walls 138, 154 and right side walls 140, 156 each may be formedwith the appropriate truss structure and each may include upper andlower ledges 106, 108, 110, 112 that align with the forward and aft topand bottom walls 134, 150, 136, 152 for joining. After the four walls134, 136, 138, 140 for the forward truss unit 124 are joined, then theforward top wall 22 and the forward bottom wall 24 may be machined asneeded to complete the forward upper truss structure 36 and the forwardlower truss structure 46. Likewise with the aft truss unit 126. Thepylon 10 may further assembled by joining the forward truss unit 124 andthe aft truss unit 126 to the central engine mount interface 128, asdescribed above, with the spigot fitting 130 and the aft wing attachmentfitting 132 being attached as well.

In various embodiments, the central engine mount interface 128, thespigot fitting 130, and the aft wing attachment fitting 132 may beformed as described above. However, the forward truss unit 124 and theaft truss unit 126 may be formed from two halves of each unit, as shownin FIG. 21. Thus, the forward truss unit 124 may include a left forwardtruss unit 178 and a right forward truss unit 180 that are formed bydividing the forward truss unit 124 along a vertical plane through thecentral longitudinal axis. Similarly, the aft truss unit 126 may includea left aft truss unit 182 and a right aft truss unit 184 that are formedby dividing the aft truss unit 126 along a vertical plane through thecentral longitudinal axis. The four half units 178, 180, 182, 184 mayeach be manufactured by casting them to be in their net shape. The twoforward half units 178, 180 are joined to create the forward truss unit124, and the two aft half units 182, 184 are joined to create the afttruss unit 126. Then, the pylon 10 is assembled by joining the forwardtruss unit 124, the aft truss unit 126, the central engine mountinterface 128, the spigot fitting 130, and the aft wing attachmentfitting 132 as discussed above.

In a fourth embodiment shown in FIGS. 22-25, the pylon 10 may include atop wall 190, a bottom wall 192, a left side wall 194, and a right sidewall 196. These walls may be substantially similar to the like-namedwalls described above and may be used to assemble the pylon 10 of otherembodiments, such as the pylon 10 shown in FIGS. 2, 17, and 19. However,the walls 190, 192, 194, 196 may have the following differences from thelike-named walls described above. The left side wall 194 may not includethe left upper ledge 106 and the left lower ledge 108. The right sidewall 196 may not include the right upper ledge 110 and the right lowerledge 112. As seen in FIG. 24, along the two lengthwise edges of eachwall 190, 192, 194, 196, there may be an inner beveled surface 198, anouter beveled surface 200, and a mitered surface 202. The inner beveledsurface 198 may extend at an angle from the inner surface of each wall190, 192, 194, 196 and toward the interior of the pylon 10. The outerbeveled surface 200 may extend at an angle from the exterior surface ofeach wall 190, 192, 194, 196 and generally in the same direction as theinner beveled surface 198 toward the interior of the pylon 10. Invarious embodiments, the inner beveled surface 198 and the outer beveledsurface 200 may be parallel to one another. The mitered surface 202generally couples the inner beveled surface 198 to the outer beveledsurface 200. The mitered surface 202 may be oriented at a right angle tothe inner beveled surface 198 and the outer beveled surface 200,although other orientations are also possible.

Furthermore, the mitered surface 202 may be oriented at an angle that ishalf of the angle between two adjoining walls 190, 192, 194, 196 of thepylon 10. For example, if the top wall 190 is joined to the left sidewall 194 at an angle of approximately 90°, then the correspondingmitered surfaces 202 of the top wall 190 and the left side wall 194 maybe oriented at approximately 45°. In various embodiments, the top wall190 may be wider than the bottom wall 192, with the left side wall 194and the right side wall 196 being of equal widths. Therefore, the anglebetween the top wall 190 and the left and right side walls 194, 196 maybe less than approximately 90°, and the corresponding mitered surfaces202 of the top wall 190 and the left and right side walls 194, 196 maybe oriented at less than approximately 45°. Additionally, the anglebetween the bottom wall 192 and the left and right side walls 194, 196may be greater than approximately 90°, and the corresponding miteredsurfaces 202 of the bottom wall 190 and the left and right side walls194, 196 may be oriented at greater than approximately 45°. Depending onthe difference in width between the top wall 190 and the bottom wall192, the mitered surfaces 202 of all the walls 190, 192, 194, 196 mayrange from approximately 30° to approximately 60°.

The walls 190, 192, 194, 196 may be first formed to include the innerbeveled surface 198, the outer beveled surface 200, and the miteredsurface 202, as shown in FIG. 23, by machining the edges, by castingeach wall 190, 192, 194, 196 to include the surfaces 198, 200, 202, orby a similar process. The walls 190, 192, 194, 196 may include the trussstructures 36, 46, 54, 66, or the structures 36, 46, 54, 66 may beformed after the joining process. Then, the walls 190, 192, 194, 196 maybe joined together as shown in FIG. 22 by joining the mitered surfaces202 of one wall with the mitered surfaces 202 of the adjacent walls suchthat the joint 114 occurs between the mitered surfaces 202. Thus thejoint 114 may be oriented at the same angle as the mitered surfaces 202.The joining process may include welding using electron-beam welding orsimilar welding techniques for use with titanium and titanium alloys.Once the walls 190, 192, 194, 196 are joined to form the pylon 10, theinner beveled surface 198 of adjoining walls may be aligned to form asubstantially continuous inner beveled surface 198 from wall to wall onthe interior corners of the pylon 10. Likewise, the outer beveledsurface 200 of adjoining walls may be aligned to form a substantiallycontinuous outer beveled surface 200 from wall to wall on the exteriorcorners of the pylon 10.

The outer beveled surfaces 200 of each wall 190, 192, 194, 196 may alsoinclude a small amount of sacrificial joint material 122. The thicknessof the sacrificial material 122 may range from approximately 0.1 inchesto 0.3 inches. After the joining process is complete, the sacrificialmaterial 122 may be removed from the outer beveled surface 200 and theouter portion of the joint 114.

In various embodiments, each wall 190, 192, 194, 196 may further includea splatter guard 204, as shown in FIG. 25. The splatter guard 204 may bepositioned along one inner beveled surface 198 of each wall 190, 192,194, 196 and oriented such that when the walls 190, 192, 194, 196 arejoined together to form the pylon 10, each inner corner of the pylon 10includes one splatter guard 204. In some embodiments, there may be asplatter guard 204 along both inner beveled surfaces 198 of opposingwalls. For example, the top wall 190 and the bottom wall 192 may eachinclude the splatter guard 204 along both inner beveled surfaces 198.Alternatively, the left side wall 194 and the right side wall 196 mayeach include the splatter guard 204 along both inner beveled surfaces198. In either case, when the walls 190, 192, 194, 196 are joinedtogether to form the pylon 10, each inner corner of the pylon 10includes one splatter guard 204.

The splatter guard 204 may include an additional amount of wall materialthat is formed along the inner beveled surface 198 and extends outwardbeyond the mitered surface 202, such that when the walls 190, 192, 194,196 are joined together, the splatter guard 204 covers the edge of thejoint 114 that faces the interior of the pylon 10, as seen in FIG. 25.Typically, the joint 114 is formed between the mitered surface 202 oftwo walls 190, 192, 194, 196. If the joining process includes welding,particularly e-beam welding, then, without the splatter guard 204,molten material may be ejected from the joint 114 along the miteredsurface 202 into the interior of the pylon 10 while the welding isoccurring. The splatter guard 204 prevents the ejection of moltenmaterial during welding. Once the joining process is complete, thesplatter guard 204 may be removed by machining techniques or the like.

The pylon 10 that utilizes the walls 190, 192, 194, 196 of the fourthembodiment benefits from ease of assembly as a result of the simplerjoints 114 that are made during the joining process. Furthermore, thewalls 190, 192, 194, 196 may be simpler to manufacture than the walls22, 24, 26, 28, and thus may be lower cost.

At least a portion of the steps of a first method 2600 for creating anaircraft engine pylon 10 in accordance with various embodiments of thepresent invention is listed in FIG. 26. The steps may be performed inthe order as shown in FIG. 26, or they may be performed in a differentorder. Furthermore, some steps may be performed concurrently as opposedto sequentially.

In connection with steps 2601-2604, a top wall 190, a bottom wall 192, aleft side wall 194, and a right side wall 196 may be formed with amitered surface 202 along each of two opposing sides. The walls 190,192, 194, 196 may further include an inner beveled surface 198 and anouter beveled surface 200 along each of two opposing sides with themitered surface 202 positioned between the inner beveled surface 198 andthe outer beveled surface 200.

In connection with step 2605, a splatter guard 204 may be formed alongone edge of each wall 190, 192, 194, 196 adjacent to the mitered surface202. The splatter guard 204 may also be formed along the inner beveledsurface 200.

In connection with step 2606, the walls 190, 192, 194, 196 arepositioned to be joined with one another such that the mitered surfaces202 of each wall 190, 192, 194, 196 are aligned with the miteredsurfaces 202 of the adjacent walls 190, 192, 194, 196 and the splatterguards 204 are positioned in the interior corners of the pylon 10. Theinner beveled surfaces 198 of adjacent walls are aligned with oneanother, and the outer beveled surfaces 200 of adjacent walls 190, 192,194, 196 are aligned with one another.

In connection with step 2607, the walls 190, 192, 194, 196 are joinedtogether such that no material is ejected into the interior of the pylon10. During the joining process, a joint 114 is formed betweencorresponding mitered surfaces 202 of adjacent walls 190, 192, 194, 196.The splatter guard 204 blocks the path from the joint 114 to theinterior of the pylon 10. The joining of the walls 190, 192, 194, 196may be performed using welding, in particular, electron-beam welding.

In connection with step 2608, the splatter guards 204 are removed afterthe walls 190, 192, 194, 196 are joined together. The splatter guards206 may be removed by machining techniques.

At least a portion of the steps of a second method 2700 for creating anaircraft engine pylon 10 in accordance with various embodiments of thepresent invention is listed in FIG. 27. The steps may be performed inthe order as shown in FIG. 27, or they may be performed in a differentorder. Furthermore, some steps may be performed concurrently as opposedto sequentially.

With reference to FIG. 5, in connection with step 2701, a left side wall26 is formed including a left truss structure 54, a left upper ledge106, and a left lower ledge 108 with a tab 118 at opposing ends of theleft upper ledge 106 and the left lower ledge 108. The left side wall 26may be formed by forging, casting, or machining. In connection with step2702, a right side wall 28 is formed including a right truss structure66, a right upper ledge 110, and a right lower ledge 112 with a tab 118at opposing ends of the right upper ledge 110 and the right lower ledge112. The right side wall 28 may be formed by forging, casting, ormachining.

With reference to FIGS. 6 and 7, in connection with step 2703, a solidtop wall 22 including a pair of tabs 118 at opposing ends is joined withthe left upper ledge 106 and the right upper ledge 110 with a jointoccurring between the tabs 118. There may be one joint 114 between thetop wall 22 and the left upper ledge 106 and one joint 114 between thetop wall 22 and the right upper ledge 110. The joining may includee-beam welding or other welding techniques used with titanium ortitanium alloys. In connection with step 2704, a solid bottom wall 24including a pair of tabs 118 at opposing ends is joined with the leftlower ledge 108 and the right lower ledge 112 with the joint occurringbetween the tabs 118. There may be one joint 114 between the bottom wall24 and the left lower ledge 108 and one joint 114 between the bottomwall 24 and the right lower ledge 112.

With reference to FIGS. 8 and 9, in connection with step 2705, an uppertruss structure 36 is formed in the top wall 22 with at least a portionof the upper truss structure 36 located in the left upper ledge 106 andat least a portion of the upper truss structure 36 located in the rightupper ledge 110. The upper truss structure 36 may be formed bymachining. In connection with step 2706, a lower truss structure 46 isformed in the bottom wall 24 with at least a portion of the lower trussstructure 46 located in the left lower ledge 108 and at least a portionof the lower truss structure 46 located in the right lower ledge 112.The lower truss structure 46 may be formed by machining.

In connection with step 2707, all the tabs 118 are removed from thepylon 10. The tabs 118 may be included to facilitate the joining processand may thus be removed after the joining process is complete. Inconnection with step 2708, a plurality of wing attachment lugs 186 and aplurality of engine attachment lugs 188 are joined to the pylon 10. Oneor more wing attachment lugs 186 may be a part of a closeout fitting 30,32. The wing attachment lugs 186 and the engine attachment lugs 188 maybe joined by welding or with fasteners.

At least a portion of the steps of a third method 2800 for creating anaircraft engine pylon 10 in accordance with various embodiments of thepresent invention is listed in FIG. 28. The steps may be performed inthe order as shown in FIG. 28, or they may be performed in a differentorder. Furthermore, some steps may be performed concurrently as opposedto sequentially.

With reference to FIG. 10, in connection with step 2801, a left sidewall 26 is formed including a left truss structure 54, a left upperledge 106, and a left lower ledge 108 with a tab 118 at opposing ends ofthe left upper ledge 106 and the left lower ledge 108. The left sidewall 26 may be formed by forging, casting, or machining. In connectionwith step 2802, a right side wall 28 is formed including a right trussstructure 66, a right upper ledge 110, and a right lower ledge 112 witha tab 118 at opposing ends of the right upper ledge 110 and the rightlower ledge 112. The right side wall 28 may be formed by forging,casting, or machining.

In connection with step 2803, a top wall 22 is formed including at leasta portion of an upper truss structure 36 with a pair of tabs 118 atopposing ends of the top wall 22. The top wall 22 may be formed byforging, casting, or machining. In connection with step 2804, a bottomwall 24 is formed including at least a portion of a lower trussstructure 46 with a pair of tabs 118 at opposing ends of the bottom wall24. The bottom wall 24 may be formed by forging, casting, or machining.

With reference to FIGS. 11 and 12, in connection with step 2805, the topwall 22 is joined with the left upper ledge 106 and the right upperledge 110 with a joint 114 occurring between the tabs 118. There may beone joint 114 between the top wall 22 and the left upper ledge 106 andone joint 114 between the top wall 22 and the right upper ledge 110. Thejoining may include e-beam welding or other welding techniques used withtitanium or titanium alloys. In connection with step 2806, the bottomwall 24 is joined with the left lower ledge 108 and the right lowerledge 112 with the joint occurring between the tabs 118. There may beone joint 114 between the bottom wall 24 and the left lower ledge 108and one joint 114 between the bottom wall 24 and the right lower ledge112.

In connection with step 2807, a portion of the upper truss structure 36is formed on the left upper ledge 106 and the right upper ledge 110. Theupper truss structure 36 may be formed by machining. In connection withstep 2808, a portion of the lower truss structure 46 is formed on theleft lower ledge 108 and the right lower ledge 112. The lower trussstructure 46 may be formed by machining.

In connection with step 2809, all the tabs 118 are removed from thepylon 10. The tabs 118 may be included to facilitate the joining processand may thus be removed after the joining process is complete. Inconnection with step 2810, a plurality of wing attachment lugs 186 and aplurality of engine attachment lugs 188 are joined to the pylon 10. Oneor more wing attachment lugs 186 may be a part of a closeout fitting 30,32. The wing attachment lugs 186 and the engine attachment lugs 188 maybe joined by welding or with fasteners.

At least a portion of the steps of a fourth method 2900 for creating anaircraft engine pylon 10 in accordance with various embodiments of thepresent invention is listed in FIG. 29. The steps may be performed inthe order as shown in FIG. 29, or they may be performed in a differentorder. Furthermore, some steps may be performed concurrently as opposedto sequentially.

With reference to FIGS. 15 and 16, in connection with step 2901, a leftside wall 26 is formed including a left truss structure 54, a left upperledge 106 that includes at least a portion of an upper truss structure36, and a left lower ledge 108 that includes at least a portion of alower truss structure 46. The left side wall 26 may also include a tab118 at the opposing ends of the left upper ledge 106 and the left lowerledge 108, and may further include sacrificial joint material 122 in theupper truss structure 36 and the lower truss structure 46. The left sidewall 26 may be formed by forging, casting, or machining. In connectionwith step 2902, a right side wall 28 is formed including a right trussstructure 66, a right upper ledge 110 that includes at least a portionof the upper truss structure 36, and a right lower ledge 112 thatincludes at least a portion of the lower truss structure 46. The rightside wall 28 may also include a tab 118 at the opposing ends of theright upper ledge 110 and the right lower ledge 112, and may furtherinclude sacrificial joint material 122 in the upper truss structure 36and the lower truss structure 46. The right side wall 28 may be formedby forging, casting, or machining.

In connection with step 2903, a top wall 22 is formed including at leasta portion of the upper truss structure 36 that also includes sacrificialjoint material 122 and a pair of tabs 118 at opposing ends of the topwall 22. The top wall 22 may be formed by forging, casting, ormachining. In connection with step 2904, a bottom wall 24 is formedincluding at least a portion of the lower truss structure 46 that alsoincludes sacrificial joint material 122 and a pair of tabs 118 atopposing ends of the bottom wall 24. The bottom wall 24 may be formed byforging, casting, or machining.

In connection with step 2905, the top wall 22 is joined with the leftupper ledge 106 and the right upper ledge 110 with a plurality of joints114 occurring between the tabs 118 and the sacrificial joint material122. There may be space between the portions of the sacrificial jointmaterial 122 along a line 116 where the top wall 22 is joined to theleft upper ledge 106 and the right upper ledge 110, thus requiring theplurality of joints 114 to be made. The joining may include e-beamwelding or other welding techniques used with titanium or titaniumalloys. In connection with step 2906, the bottom wall 24 is joined withthe left lower ledge 108 and the right lower ledge 112 with a pluralityof joints 114 occurring between the tabs 118 and the sacrificial jointmaterial 122. There may be space between the portions of the sacrificialjoint material 122 along the line 116 where the bottom wall 24 is joinedto the left lower ledge 108 and the right lower ledge 112, thusrequiring the plurality of joints 114 to be made.

In connection with step 2907, all the tabs 118 and the sacrificial jointmaterial 122 are removed from the pylon 10. The tabs 118 and thesacrificial joint material 122 may be included to facilitate the joiningprocess and may thus be removed after the joining process is complete.In connection with step 2908, a plurality of wing attachment lugs 186and a plurality of engine attachment lugs 188 are joined to the pylon10. One or more wing attachment lugs 186 may be a part of a closeoutfitting 30, 32. The wing attachment lugs 186 and the engine attachmentlugs 188 may be joined by welding or with fasteners.

At least a portion of the steps of a fifth method 3000 for creating anaircraft engine pylon 10 in accordance with various embodiments of thepresent invention is listed in FIG. 30. The steps may be performed inthe order as shown in FIG. 30, or they may be performed in a differentorder. Furthermore, some steps may be performed concurrently as opposedto sequentially.

With reference to FIG. 21, in connection with step 3001, a left sidewall 26 is formed including a left truss structure 54, a left upperledge 106 that includes at least a portion of an upper truss structure36, and a left lower ledge 108 that includes at least a portion of alower truss structure 46. The left side wall 26 may be formed byforging, casting, or machining. In connection with step 3002, a rightside wall 28 is formed including a right truss structure 66, a rightupper ledge 110 that includes at least a portion of the upper trussstructure 36, and a right lower ledge 112 that includes at least aportion of the lower truss structure 46. The right side wall 28 may beformed by forging, casting, or machining.

In connection with step 3003, the left side wall 26 is joined with theright side wall 28 such that the first portion of the upper trussstructure 36 is joined with the second portion of the upper trussstructure 36, and the first portion of the lower truss structure 46 isjoined with the second portion of the lower truss structure 46. Aplurality of joints 114 may be made to join the portions of the uppertruss structure 36 and the portions of the lower truss structure 46. Inconnection with step 3004, a plurality of wing attachment lugs 186 and aplurality of engine attachment lugs 188 are joined to the pylon 10. Oneor more wing attachment lugs 186 may be a part of a closeout fitting 30,32. The wing attachment lugs 186 and the engine attachment lugs 188 maybe joined by welding or with fasteners.

At least a portion of the steps of a sixth method 3100 for creating anaircraft engine pylon 10 in accordance with various embodiments of thepresent invention is listed in FIG. 31. The steps may be performed inthe order as shown in FIG. 31, or they may be performed in a differentorder. Furthermore, some steps may be performed concurrently as opposedto sequentially.

With reference to FIG. 21, in connection with step 3101, a forward trussunit 124 configured to couple the pylon 10 to a portion of an aircraftengine 12 is formed. The forward truss unit 124 may be formed by thejoining of a left forward truss unit 178 and a right forward truss unit180. The left forward truss unit 178 and the right forward truss unit180 may be formed by forging, casting, or machining. In connection withstep 3102, an aft truss unit 126 configured to couple the pylon 10 to aportion of an aircraft wing 14 is formed. The aft truss unit 126 may beformed by the joining of a left aft truss unit 182 and a right aft trussunit 184. The left aft truss unit 182 and the right aft truss unit 184may be formed by forging, casting, or machining. In connection with step3103, a central engine mount interface 128 configured to couple thepylon 10 to a portion of the aircraft engine 12.

In connection with step 3104, the aft portion of the forward truss unit124 is joined to the central engine mount interface 128. In connectionwith step 3105, the forward portion of the aft truss unit 126 is joinedto the central engine mount interface 128. The joining process mayinclude e-beam welding or other welding techniques used with titanium ortitanium alloys.

Although the invention has been described with reference to theembodiments illustrated in the attached drawing figures, it is notedthat equivalents may be employed and substitutions made herein withoutdeparting from the scope of the invention as recited in the claims.

Having thus described various embodiments of the invention, what isclaimed as new and desired to be protected by Letters Patent includesthe following:

1. An aircraft engine pylon, the pylon comprising: a top wall includinga connection tab at each of four corners of the top wall; a bottom wallincluding a connection tab at each of four corners of the bottom wall; aleft side wall including a left upper ledge aligned with the top wall,the left upper ledge including a connection tab at each of two opposingends of the left upper ledge that align with two of the tabs of the topwall, and a left lower ledge aligned with the bottom wall, the leftlower ledge including a connection tab at each of two opposing ends ofthe left lower ledge that align with two of the tabs of the bottom wall;a right side wall including a right upper ledge aligned with the topwall, the right upper ledge including a connection tab at each of twoopposing ends of the right upper ledge that align with two of the tabsof the top wall, and a right lower ledge aligned with the bottom wall,the right lower ledge including a connection tab at each of two opposingends of the right lower ledge that align with two of the tabs of thebottom wall.
 2. The pylon of claim 1, further including an upper trussstructure formed in the left upper ledge, the right upper ledge, and thetop wall.
 3. The pylon of claim 2, wherein the upper truss structureincludes a plurality of truss members and a plurality of truss nodeswherein each of the truss nodes couples to a portion of the trussmembers and such that a portion of the truss nodes are formed in theleft upper ledge, and a portion of the truss nodes are formed in theright upper ledge.
 4. The pylon of claim 1, further including a lowertruss structure formed in the left lower ledge, the right lower ledge,and the bottom wall.
 5. The pylon of claim 4, wherein the lower trussstructure includes a plurality of truss members and a plurality of trussnodes wherein each of the truss nodes couples to a portion of the trussmembers and such that a portion of the truss nodes are formed in theleft lower ledge, and a portion of the truss nodes are formed in theright lower ledge.
 6. The pylon of claim 1, further including a lefttruss structure formed in the left side wall.
 7. The pylon of claim 1,further including a right truss structure formed in the right side wall.8. The pylon of claim 1, further including an engine attachmentinterface coupled to the bottom wall, the left side wall, and the rightside wall and configured to couple the pylon to the aircraft engine. 9.The pylon of claim 1, further including a plurality of wing attachmentlugs coupled to the top wall, the left side wall, and the right sidewall and configured to couple the pylon to an aircraft wing.
 10. Anaircraft engine pylon, the pylon comprising: a top wall including anupper truss structure and a connection tab at each of four corners ofthe top wall; a bottom wall including a lower truss structure and aconnection tab at each of four corners of the bottom wall; a left sidewall including a left truss structure, the left side wall including aconnection tab at each of four corners of the left side wall, whereintwo of the tabs align with two tabs of the top wall and the other twotabs align with two tabs of the bottom wall; and a right side wallincluding a right truss structure, the right side wall including aconnection tab at each of four corners of the right side wall, whereintwo of the tabs align with two tabs of the top wall and the other twotabs align with two tabs of the bottom wall.
 11. The pylon of claim 10,further including an engine attachment interface coupled to the bottomwall, the left side wall, and the right side wall and configured tocouple the pylon to the aircraft engine.
 12. The pylon of claim 10,further including a plurality of wing attachment lugs coupled to the topwall, the left side wall, and the right side wall and configured tocouple the pylon to an aircraft wing.
 13. An aircraft engine pylon, thepylon comprising: a monolithic top wall including an upper trussstructure and a connection tab at each of four corners of the top wall;a monolithic bottom wall including a lower truss structure and aconnection tab at each of four corners of the bottom wall; a monolithicleft side wall including a left truss structure, the left side wallincluding a connection tab at each of four corners of the left sidewall, wherein two of the tabs align with two tabs of the top wall andthe other two tabs align with two tabs of the bottom wall; and amonolithic right side wall including a right truss structure, the rightside wall including a connection tab at each of four corners of theright side wall, wherein two of the tabs align with two tabs of the topwall and the other two tabs align with two tabs of the bottom wall. 14.The pylon of claim 13, further including an engine attachment interfacecoupled to the bottom wall, the left side wall, and the right side walland configured to couple the pylon to the aircraft engine.
 15. The pylonof claim 13, further including a plurality of wing attachment lugscoupled to the top wall, the left side wall, and the right side wall andconfigured to couple the pylon to an aircraft wing.